My earlier U.S. Pat. No. 4,627,863 is directed to an industrial filtration apparatus for use in factory installations to reduce the concentration of particulate matter and other foreign materials in the airstream entering the ventilating system of the plant. This system is particularly effective for use in plants which recirculate the ventilating medium through a central ventilating system.
In many workshops, both in the home and in industrial installations, the workshop is not connected to a central ventilating system and the air in the shop is subject to the buildup of entrained particulate matter generated by the operations conducted in the workshop. For example, in a woodworking shop the operation of power tools and equipment generates a substantial quantity of sawdust which may be entrained in the air and provide a generally unhealthy concentration of sawdust. Exhaust fans are effective to remove the contaminated air, but generally the volume of air handled by exhaust fans is not sufficient to maintain a reasonably clean atmosphere within the workshop. Furthermore, the exhaust fans may become fouled with the particulate matter which is deposited on the mechanism as the air passes through it.
While it is possible to provide an air-handling system for the workshop which will enable the filtration and recirculation of the ambient air in the workshop, such systems are expensive and are not economical, particularly when the workshop is used only sporadically.
Furthermore, the equipment which generates the pollution in the air may be located in different areas of the workshop, and may be operated at different times. Accordingly, the need for the air-cleaning device is not continuous and it would be desirable to provide a unit which may be moved to the vicinity of the apparatus which is causing the air pollution.